WO2013081151A1

WO2013081151A1 - Method for evaluating coated film thickness and coating range of wax, and coating inspection system

Info

Publication number: WO2013081151A1
Application number: PCT/JP2012/081209
Authority: WO
Inventors: 中田　裕二; 信久塚本; 公志高垣; 貴紀川村
Original assignee: ダイハツ工業株式会社
Priority date: 2011-11-30
Filing date: 2012-11-30
Publication date: 2013-06-06
Also published as: CN103988047B; CN103988047A; MY184816A

Abstract

A method for evaluating coated film thickness of wax is provided with: a temperature acquisition step for acquiring the front surface temperature of a member to be coated that has not been coated with the wax and the back surface temperature of a region coated with the wax by capturing an image of the member to be coated by an infrared thermograph; an actual temperature difference calculation step for calculating the actual temperature difference between the back surface temperature of the coated region and the front surface temperature before the coating; a theoretical formula derivation step for, on the basis of a coating condition of the wax for the member to be coated, derives a theoretical formula indicating the relation between the temperature difference between the back surface temperature of the coated region and the front surface temperature before the coating, and the coated film thickness of the wax; and a coated film thickness evaluation step for evaluating the actual coated film thickness of the wax from the actual temperature difference using the theoretical formula.

Description

Wax coating thickness and coating range evaluation method, and coating inspection system

The present invention relates to a method for evaluating a coating thickness and a coating range of a wax, and a coating inspection system, and in particular, a method for evaluating a coating thickness and a coating range of a wax to be applied to an invisible place, and a temperature of a coating region. The present invention relates to a coating inspection system for inspecting a coating operation based on a distribution.

For example, in a car body painting process, a rust-preventing wax is used after the painting process to prevent the corrosion of steel sheets due to the intrusion of rainwater, etc., into bag structures such as doors and hoods that make up the car body. There is provided a rust-proofing process for applying the coating.

As described above, the purpose of applying this type of wax is to prevent rust, so after the wax application operation, whether or not the wax is properly applied, specifically, the applied wax is sufficient. It is necessary to inspect whether or not the coating film thickness is such that sufficient rust prevention performance can be exhibited, or whether or not it is applied within a range where sufficient rust prevention performance can be exhibited. However, since the application location of the wax is the inner surface of the bag structure such as a door or a hood, the range that can be directly confirmed visually is limited. Therefore, it is difficult to confirm the coating thickness of the entire region, and it is difficult to confirm the coating range without omission. Therefore, for this type of inspection, the amount of coating (coating film thickness or the area of the area that can actually be applied) is determined by the amount of wax dripping from the drain hole provided in the member to be coated (door, etc.). The current situation is that they are indirectly evaluated.

In addition to this, a certain number is regularly extracted, and inspection by endoscope and visual confirmation by disassembly are performed, but the number of confirmations is inevitably reduced in each method, and the degree of variation is unknown For this reason, it has been difficult to say that sufficient quality assurance has been achieved by the total amount evaluation.

On the other hand, not only wax, but also various coatings and sealers are applied to various components that make up the body of an automobile for the purpose of improving design such as appearance and functionality such as sealing and rust prevention. Work is being done. Since these application states greatly affect the quality and performance of the member to be applied, an inspection of the application state is performed at the time of application or after application to determine the quality.

Here, in the inspection of the coating operation, various inspection means such as a visual inspection by an operator and a method for judging the quality based on an image obtained by an imaging means such as a camera are actually adopted. Has reached. On the other hand, when performing application work on bag-like members such as hoods and door panels, since the coating material such as wax is applied to the inside of the bag-like member, the inside application state is also inspected. Need to be done. However, it is difficult to check the internal coating state by visual observation by an operator or an imaging means such as a normal camera.

Therefore, in order to solve these problems, Patent Document 1 below discloses a method for evaluating the application state of wax by analyzing an image obtained by imaging an application site of a vehicle body with an infrared thermograph. ing. Specifically, this evaluation method divides an image obtained by imaging with an infrared thermograph into pixel units, calculates a temperature increase rate for each divided unit pixel, and sets this in advance 2 Compared with two thresholds, the temperature rise in the unit pixel is due to the direct application of wax (if it is greater than the higher threshold) or due to thermal diffusion from the wax (up and down This is a method for specifying the range of the application distribution by determining whether the value is between threshold values. The series of processes is performed by a data processing apparatus that stores an analysis algorithm for performing the processes and can transmit thermal image data obtained by imaging with an infrared camera.

JP 2010-112806 A

As described above, according to the evaluation technique described in Patent Document 1, it is possible to evaluate the application state of the wax without destroying the application target (such as a door). It is only a range, and does not accurately evaluate the coating film thickness. This is because the relationship between the temperature increase rate and the coating film thickness is not clarified. Also, since the surface temperature of the vehicle body as the application target flowing on the production line varies, even if the relationship between the temperature increase rate and the coating film thickness is known, the temperature increase rate on the back surface of the coating area is always constant. It is difficult to evaluate with the standard (threshold value).

For example, a method of measuring the coating film thickness using a non-contact measuring device such as a laser displacement meter is not conceivable, but this type of measuring device is expensive, and such a device is used. However, the measurement of the coating film thickness in the bag structure is still very difficult. Furthermore, since control and adjustment may be complicated, it is not suitable for measuring the coating film thickness of the wax as in the present case.

In addition, regarding the evaluation of the application range, the evaluation technique described in Patent Document 1 requires time for analyzing the captured image after the work is completed in order to evaluate the application range using the temperature increase rate. Become. In this case, the application range cannot be evaluated until after the analysis time has elapsed, resulting in an increase in work time and consequently an increase in work cost. Further, when the member to be coated is a door or hood of a vehicle body, it is desirable that a plurality of workers are simultaneously applied to the plurality of doors and hood. However, in such a case, even if an image of the back surface of the predetermined wax application area is continuously captured for a certain period of time immediately after application, other workers, doors, etc. are obstructed, so that the image is continuously captured as described above. Difficult to do. In this case, it is necessary to perform the door coating operation and the image capturing operation one by one, and the work time is increased as in the case described above.

Further, according to the inspection method described in Patent Document 1, it is possible to automatically specify the application region by performing a certain process on the thermal image data obtained by imaging with the infrared camera. However, if this type of application work is performed on an area that is not visible to the operator (inside the bag-like member), there is a high possibility that an unpainted area will occur, and therefore, an unpainted area remains. In many cases, it is necessary to re-apply (re-apply) the region where the ink has occurred. In the inspection method described in Patent Document 1, a monitor for displaying a temperature distribution is provided in the data processing apparatus, but the arrangement position is not particularly described. A personal computer is used as a data processing device. In this way, when the configuration is not such that the inspection result can be directly checked by the coating operator, for example, when repainting is necessary, information necessary for the repainting (there is unpainted at that time) It is difficult for the coating operator to grasp the area) accurately and quickly.

In view of the above circumstances, the first technical problem to be solved by the present invention is to evaluate the total thickness of the coated film of wax by a simple method.

Also, in view of the above circumstances, the second technical problem to be solved by the present invention is to evaluate the total number of wax application areas in a short time.

In view of the above circumstances, it is a third technical problem to be solved by the present invention to provide a coating inspection system in which a coating operator can accurately and quickly grasp the inspection result of a coating operation. .

The solution of the first technical problem is achieved by the method for evaluating the coating thickness of the wax according to the first aspect of the present invention. That is, in this evaluation method, the surface temperature of the non-application region where the wax is not applied among the members to be coated and the back surface temperature of the region where the wax is applied are obtained by imaging the member to be coated with an infrared thermograph. The temperature acquisition step, the actual temperature difference calculating step for calculating the actual temperature difference between the back surface temperature of the application region and the surface temperature of the non-application region, and the back surface of the application region based on the wax application conditions for the member to be applied. The theoretical formula derivation process for deriving the theoretical formula showing the relationship between the temperature difference between the temperature and the surface temperature of the non-coating area and the coating thickness of the wax, and the actual coating film of the wax from the actual temperature difference using the theoretical formula It is characterized by having a coating film thickness evaluation step for evaluating the thickness.

¡Doors, hoods, etc., to which wax is applied are usually formed from thin steel plates. In addition, since the wax application operation is performed on a predetermined area while scanning the wax application gun, a certain time is required from the start of application to the end of application. Therefore, heat transfer from the applied wax to the member to be applied is performed in the wax application area immediately after the start of the application work, and after the application work is completed, the back surface temperature of the application area is actually imaged with an infrared thermograph. When it becomes possible, it is presumed that the wax and the application region of the member to be applied have reached an isothermal state or a state close thereto. Further, the temperature rise of the member to be coated at this time tends to increase as the amount of heat of the applied wax, that is, the amount of applied wax increases. In view of the above points, the present inventors have determined that the temperature difference between the back surface temperature of the coated region after the wax is coated on the coated member and the surface temperature of the region where the wax is not coated, and the application of the wax Finding the theoretical formula between the film thickness and evaluating the actual coating film thickness based on this theoretical formula, the knowledge that the evaluation of the wax coating film thickness can be carried out with high accuracy for all vehicles I came to get.

The present invention was made on the basis of the above knowledge, and the theoretical formula in which a certain consistency was confirmed between the temperature difference between the coated area and the non-coated area of the wax and the measured value of the coated film thickness. Since the evaluation standard of the coating film thickness is determined using the above, it is possible to perform highly accurate and reliable film thickness evaluation while minimizing the influence of temperature variation for each member to be coated. In addition, since the coating film thickness can be evaluated by measuring the back surface temperature of the coating area of the coated member and the surface temperature of the non-coating area using an infrared thermograph, the coating film thickness is difficult to visually observe. However, it can be easily and accurately evaluated. In addition, since it is only necessary to measure the surface temperature of the area where the wax is not applied and the back surface temperature of the application area after a certain time has elapsed after application, the measurement operation itself can be performed non-destructively and can be performed in a short time. . Therefore, it is possible to evaluate the total number of coating film thicknesses without causing a special increase in work time, and it is possible to further improve the quality assurance function. Of course, since the only necessary measuring instrument is an infrared thermograph, a significant increase in equipment cost can be avoided.

In addition, the method for evaluating the coating thickness of the wax according to the first aspect of the present invention acquires the surface temperature of the member to be coated before applying the wax as the surface temperature of the non-application region in the temperature acquisition step. May be.

As described above, by obtaining the surface temperature of the member to be coated before applying the wax as the non-application region, the coating film thickness can be evaluated based on the temperature difference before and after the application in the wax application planned region. Thereby, the coating film thickness of the wax can be evaluated with reference to the surface temperature of the member to be coated that is not affected at all by the heat transfer due to the wax coating (no temperature change is caused). Moreover, stable film thickness evaluation can be performed without being affected by variations in temperature for each member to be coated.

Further, as described above, when the surface temperature of the member to be coated before applying the wax is acquired as the surface temperature of the non-application region, the back surface of the region where the wax is to be applied of the member to be coated is further infrared-irradiated in the temperature acquisition step. You may make it acquire the back surface temperature of an application | coating area | region, and the surface temperature before application | coating by imaging with a thermograph.

In this way, if the temperature before and after coating is acquired by imaging the back surface of the wax coating planned area with an infrared thermograph, even if there is a variation in temperature among the coated members, wax coating is performed. It becomes possible to measure the temperature of the region most suitable for acquisition as the previous surface temperature. Therefore, the actual temperature difference corresponding to the theoretical formula can be acquired, and the evaluation accuracy of the coating film thickness can be further improved. In addition, since the relative position (imaging position) between the member to be coated and the infrared thermograph can be made constant before and after the wax application, the complexity of the equipment required for film thickness evaluation can be avoided, which also reduces the equipment cost. An increase can be avoided.

Alternatively, the method for evaluating the coating thickness of the wax according to the first aspect of the present invention acquires the surface temperature of the member to be coated excluding the area where the wax is scheduled to be applied as the surface temperature of the non-application area in the temperature acquisition step. There may be.

The gist of the present invention is based on the actual temperature difference between the wax application region and the non-application region, and the evaluation of the wax coating film thickness for which a predetermined consistency was experimentally recognized between this actual temperature difference. In view of the above, the non-application area of the wax for which the surface temperature is to be acquired is not limited to the area where the wax is scheduled to be applied. May be. Thus, by setting the area outside the planned wax application area as the surface temperature acquisition area, for example, by an operator or peripheral equipment, the wax application planned area can be stably stabilized by the infrared thermograph before and after the coating operation. Even if the image cannot be captured, the actual temperature difference can be calculated based on the surface temperature of a region of the coated member that is not directly related to the region where the wax is scheduled to be applied (for example, the upper portion of the door panel). it can. In addition, if it is an area away from the planned application area, the temperature change during the application work due to heat transfer is estimated to be very small or negligible, so not only before the application work but also during the application work Even the acquired surface temperature of the region can be used without any problem as a calculation reference for the actual temperature difference.

In addition, the method for evaluating the coating thickness of the wax according to the first aspect of the present invention includes an allowable lower limit setting step for setting an allowable lower limit of the temperature difference corresponding to the allowable lower limit of the coating thickness based on a theoretical formula. In addition, in the coating film thickness evaluation step, the area where the actual temperature difference obtained by imaging with the infrared thermograph is equal to or greater than the allowable lower limit value of the temperature difference is calculated, and only the area where the actual temperature difference is equal to or greater than the allowable lower limit value May be displayed on a monitor disposed at a position visible to the wax application worker.

As described above, it is possible to display only a portion having a coating film thickness that is actually acceptable on the monitor. As a result, the wax application operator can accurately grasp the location where the coating amount (coating film thickness) is insufficient, and the wax can be repainted immediately after the operator confirms it on the monitor. This makes it possible to perform a wax application operation including repainting in a very short time.

Also, the solution of the second technical problem is achieved by the method for evaluating the application range of the wax according to the second aspect of the present invention. That is, in this evaluation method, the surface temperature of the non-application area where the wax is not applied among the members to be applied, and the back surface temperature of the application area of the wax after a predetermined time has elapsed since the wax was applied. A temperature acquisition process that is acquired by imaging the member with an infrared thermograph, an actual temperature difference calculation process that calculates an actual temperature difference between the back surface temperature of the application area and the surface temperature of the non-application area, and application by wax application In consideration of the temperature rise in the area, the allowable lower limit setting process for setting the allowable lower limit of the temperature difference between the back surface temperature of the application area and the surface temperature of the non-application area, the actual temperature difference, and the allowable lower limit of the temperature difference And an application range evaluation step for evaluating the application range of the wax, and in the allowable lower limit setting step, taking into account the temperature increase in the non-application region due to heat transfer from the wax application region to the non-application region. Characterized with a point that the permissible lower limit value of the temperature difference.

Thus, in the present invention, based on the temperature difference between the surface temperature of the area where the wax is not applied in the member to be coated and the back surface temperature of the area where the wax is applied after a certain time has elapsed after the wax is applied. Since the application range is evaluated, the wax application range can be evaluated by performing a temperature measurement (imaging) operation once for each of the wax application region and the non-application region. As a result, the time required for the temperature measurement operation can be shortened as compared with the evaluation method using the conventional infrared thermograph that needs to continuously capture images immediately after application. In addition, since it is only necessary to measure the surface temperature of the area where the wax is not applied among the applied members and the back surface temperature of the application area after a certain time has elapsed after application, the measurement operation itself can be performed non-destructively, And it takes a short time. Therefore, it is possible to evaluate the total number of coating areas without causing a special increase in work time, and it is possible to further improve the quality assurance function.

Further, in the present invention, when setting the allowable lower limit value of the temperature difference, not only the temperature increase of the application region due to the application of the wax, but also the non-application region adjacent thereto from the wax application region (therefore obtaining the surface temperature). As a result, it may be a different area from the non-application area of the wax.) The allowable lower limit of the temperature difference is set in consideration of the temperature increase in the non-application area due to heat transfer to . In this type of wax application operation, the amount of wax actually required is not so large, while the coated member is made of a material with relatively high heat conductivity, such as a steel plate or an aluminum alloy plate. In this case, the amount of temperature increase in the non-application area due to heat transfer from the wax application area to the non-application area adjacent to the wax application area becomes a non-negligible magnitude. In view of the above points, in the present invention, the allowable lower limit value of the temperature difference is set in consideration of the temperature increase in the non-application area due to heat transfer from the application area, so that the wax is properly applied. It is possible to avoid a situation in which an area that is not present is erroneously determined as an application area. Also, when the wax application operation is prolonged or completed in a short time, the elapsed time from the start of application to imaging varies, so the actual temperature difference value varies, but as described above If the evaluation is made taking into account the temperature rise due to heat transfer to the non-application area, the wax application range can be evaluated with high accuracy regardless of the imaging time. Moreover, it becomes possible to improve the reliability with respect to the evaluation result.

Further, the wax application range evaluation method according to the present invention may acquire the surface temperature of the member to be applied before applying the wax as the surface temperature of the non-application area in the temperature acquisition step.

Thus, by obtaining the surface temperature of the member to be coated before applying the wax as the non-application area, the application range can be evaluated based on the temperature difference before and after application in the wax application scheduled area. Thereby, the application range of the wax can be evaluated based on the surface temperature of the member to be applied that is not affected by the heat transfer due to the application of the wax (no temperature change is caused). Moreover, the evaluation result of the stable coating range can be obtained without being affected by the variation in temperature for each member to be coated.

Alternatively, the wax application range evaluation method according to the present invention may acquire the surface temperature of the member to be applied excluding the wax application scheduled area as the surface temperature of the non-application area in the temperature acquisition step.

The gist of the present invention is that an allowable lower limit value of the temperature difference is taken into account by taking into account the temperature increase in the coating area due to the wax application and the temperature increase in the non-application area due to heat transfer from the wax application area to the non-application area adjacent thereto. Therefore, the wax non-application area for which the surface temperature is to be acquired is not limited to the wax application scheduled area, and is, for example, out of the wax application scheduled area of the member to be applied. It may be an area. Thus, by setting the area outside the planned wax application area as the surface temperature acquisition area, for example, by an operator or peripheral equipment, the wax application planned area can be stably stabilized by the infrared thermograph before and after the coating operation. Even if the image cannot be captured, the actual temperature difference can be calculated based on the surface temperature of a region of the coated member that is not directly related to the region where the wax is scheduled to be applied (for example, the upper portion of the door panel). it can. In addition, if it is an area away from the planned application area, the temperature change during the application work due to heat transfer is estimated to be very small or negligible, so not only before the application work but also during the application work Even the acquired surface temperature of the region can be used without any problem as a calculation reference for the actual temperature difference.

Further, the wax application range evaluation method according to the second aspect of the present invention further includes a temperature difference in the allowable lower limit setting step in consideration of a decrease in temperature of the application region over time after the wax application. The allowable lower limit value may be set.

In the area where the wax is applied, the temperature rises due to heat transfer from the wax, but after a certain period of time, the amount of heat transfer (heat diffusion) to the surroundings may exceed the amount of heat transfer from the wax. . For this reason, if the allowable lower limit of the temperature difference is set to be larger than necessary, even if the wax is properly applied, the area where the temperature decrease has already started is erroneously determined as a non-application area. May occur. In this respect, as described above, after setting the wax, the allowable lower limit value of the temperature difference is set by further taking into account the temperature drop of the application region with the passage of a certain time (that is, the time from the start of application to the start of imaging). Thus, the above-described problem (incorrect determination) can be prevented, and a more accurate evaluation of the application range can be performed.

In addition, the wax application range evaluation method according to the second aspect of the present invention includes a temperature difference between the back surface temperature of the application region and the surface temperature of the non-application region based on the wax application conditions for the member to be applied, and the wax. The method further comprises a theoretical formula deriving step for deriving a theoretical formula showing the relationship with the coating film thickness, and in the allowable lower limit setting step, based on the theoretical formula, an allowable lower limit of the temperature difference corresponding to the allowable lower limit value of the coating film thickness The theoretical value of the value is calculated, and the temperature rise in the non-application area due to heat transfer from the wax application area to the non-application area is added to the theoretical value to calculate the allowable lower limit value of the temperature difference. Also good.

Since the purpose of applying the wax is to rust prevention of the member to be coated, the lower limit value of the allowable coating film thickness is defined by standards and the like. In this respect, the theoretical value of the allowable lower limit of the temperature difference is obtained based on the theoretical formula showing the relationship between the temperature difference between the wax application area and the non-application area and the application film thickness. By adding the temperature increase in the non-application area due to heat transfer from the above and calculating the allowable lower limit value of the temperature difference, it is possible to more accurately evaluate the range in which the wax is properly applied.

In addition, the wax application range evaluation method according to the second aspect of the present invention applies the wax application only to a region where the actual temperature difference obtained by imaging with an infrared thermograph is equal to or greater than the allowable lower limit of the temperature difference. You may display on the monitor arrange | positioned in the position which an operator can visually recognize.

If done as described above, it is possible to display only the range in which the wax is actually applied properly on the monitor. Thereby, not only the area where the wax is not applied can be accurately grasped by the wax application operator, but also the wax can be reapplied immediately after being confirmed by the monitor. This makes it possible to perform a wax application operation including repainting in a very short time.

Also, the solution of the third technical problem is achieved by the coating inspection system according to the third aspect of the present invention. In other words, this inspection system is a system for inspecting the application state of the applied material to the member to be coated, and an infrared thermograph for imaging at least the coating region of the member to be coated, and visible to the coating worker. And a display unit that displays a temperature distribution of the application region acquired by imaging an infrared thermograph, and the display unit continuously displays a change over time of the temperature distribution of the application region. And a still image of a dynamic image at a predetermined time can be displayed.

As described above, in the present invention, since the display unit for displaying the temperature distribution of the application region acquired by imaging of the infrared thermograph is arranged in a range that can be visually recognized by the application operator, the application operator himself indicates the application state. It is possible to confirm and perform an inspection regarding the quality of the application work. Further, at this time, the display unit can display a dynamic image that continuously displays the change over time in the temperature distribution of the application region, so that the application operator can watch the temperature distribution of the application target member while working. Application work can be performed. Therefore, the coating operation can be performed smoothly. Further, in the present invention, since the still image at a predetermined time of the dynamic image can be displayed on the display unit, for example, the still image at the end of the application work, that is, the temperature distribution of the application region immediately after the application work is completed. It can be confirmed in a stationary state. If the temperature distribution is in a static state, it can be checked in more detail and more accurately than when judging the quality of the application state by looking at a dynamic image whose state changes from moment to moment. In addition to being able to make a quick and accurate determination, the application operator can quickly and accurately grasp the area that needs to be repainted. Of course, it is possible to check in detail whether or not repainting is good by displaying a new still image at the end of each repainting operation. Therefore, not only the initial coating operation but also the repainting inspection can be performed quickly and accurately.

Further, in the coating inspection system according to the third aspect of the present invention, the display unit may be able to display a dynamic image and a still image at the same time.

As described above, the dynamic image and the still image regarding the temperature distribution of the application region can be displayed on the one display unit at the same time, and after the still image at a certain time of the dynamic image is displayed on the display unit, The temporal change of the temperature distribution after the acquisition of the still image is continuously displayed as a dynamic image. Thus, for example, after the necessity of repainting is performed based on the still image, the coating operation can be performed while comparing the still image with the dynamic image reflecting the intermediate result of the subsequent repainting operation. Therefore, it is possible to perform the coating operation while confirming in real time the region that has already been repainted and the region that still needs repainting, and the repainting operation can be performed smoothly and quickly.

In addition, a coating inspection system according to the third aspect of the present invention includes a display instruction unit that instructs operation to display a still image on the display unit, and a conveyance instruction unit that instructs operation to convey a member to be coated by a conveying unit. May be further provided.

With this configuration, the temperature distribution after the completion of the coating operation is displayed as a still image on the display unit by operating the display instruction unit after the coating operator has completed the coating operation. Then, when the application worker himself / herself determines the quality of the application operation and determines that there is no problem (no unpainted residue), by operating the conveyance instruction unit, for example, the application target member supported by a conveyor or the like is It can be transported toward the process. On the other hand, if the application operator determines that there is a problem (there is an unpainted area) as a result of determining whether the application operation is good or not using a still image, the application operation can be performed without operating the conveyance instruction unit. Therefore, based on the judgment of the coating operator, the coated member can be transported when there is no remaining coating and it can be transported to the next process. Can be done quickly and reliably.

Further, when the coating inspection system according to the third aspect of the present invention is provided with the display instruction unit and the conveyance instruction unit, the operation of the conveyance instruction unit is performed by moving the still image on the display unit by the operation of the display instruction unit. It may be controlled to be effective only after being displayed.

As described above, when repainting is considered, it is effective to arrange the above-described configuration (display instruction unit and conveyance instruction unit) within the reach of the operator's hands, but in that case, There is a concern about mis-conveying due to a pressing error. In this regard, for example, by controlling the display instruction unit and the conveyance instruction unit as described above, even if the display instruction unit and the conveyance instruction unit are mistakenly pressed, the coated member is not conveyed. . Therefore, it is possible to avoid the situation where the member to be applied flows to the next process without performing the coating inspection, and to perform the total inspection.

As described above, according to the evaluation method according to the first aspect of the present invention, it is possible to evaluate the total coating thickness of the wax by a simple method.

Also, as described above, according to the evaluation method according to the second aspect of the present invention, it is possible to evaluate the total number of wax application ranges in a short time.

As described above, according to the inspection system according to the third aspect of the present invention, the application operator can accurately and quickly grasp the inspection result of the application operation. Further, even when repainting is required, the repainting operation can be performed quickly and accurately.

It is a flowchart of the coating film thickness evaluation method of the wax which concerns on one Embodiment of the 1st side surface of this invention. It is a perspective view which shows an example of the equipment for enforcing the coating film thickness evaluation method of wax. It is sectional drawing of the bag structure part of the door as a to-be-coated member containing the application | coating area | region of a wax. It is a graph which shows the relationship between the temperature difference of the back surface temperature of a wax application | coating area | region, and the surface temperature before application | coating, and the coating film thickness of a wax. It is a display example on the monitor of the evaluation result obtained by the coating film thickness evaluation method for wax according to an embodiment of the first aspect of the present invention. It is a display example on the monitor of the evaluation result obtained by the same coating film thickness evaluation method as FIG. 5A. It is a display example on the monitor of the evaluation result obtained by the coating film thickness evaluation method for wax according to another embodiment of the first aspect of the present invention. It is a display example on the monitor of the evaluation result obtained by the coating film thickness evaluation method for wax according to another embodiment of the first aspect of the present invention. It is an example of a display on a monitor of an evaluation result obtained by the same coating film thickness evaluation method as FIG. 7A. It is a flowchart of the application range evaluation method of the wax which concerns on one Embodiment of the 2nd side surface of this invention. It is a front view of the display part of the application | coating inspection system which concerns on one Embodiment of the 3rd side surface of this invention, Comprising: It is a figure which shows the display form of the display part at the time of application | coating operation | work. It is a front view of the display part of the same application | coating inspection system as FIG. 9A, Comprising: It is a figure which shows the display form of the display part after completion | finish of an application | coating operation | work. It is a front view of the display part of the same application | coating inspection system as FIG. 9A, Comprising: It is a figure which shows the display form of the display part after completion | finish of application | coating inspection. It is a top view which shows the example of 1 structure of a display instruction | indication part and a conveyance instruction | indication part. It is a flowchart of the inspection method using the application | coating inspection system which concerns on one Embodiment of the 3rd side surface of this invention.

Hereinafter, an embodiment of a method for evaluating a coating thickness of a wax according to a first aspect of the present invention will be described with reference to the drawings. In this embodiment, a case where the coating film thickness of the wax applied to the door of the vehicle body and the bag structure portion of the hood is evaluated will be described as an example.

FIG. 1 shows a flowchart of a method for evaluating a coating thickness of a wax according to an embodiment of the first aspect of the present invention. As shown in FIG. 1, in this evaluation method, the surface temperature of the member to be coated before applying the wax and the back surface temperature of the region to which the wax is applied are obtained by imaging the member to be coated with an infrared thermograph. The temperature acquisition step S11, the actual temperature difference calculation step S12 for calculating the actual temperature difference between the back surface temperature of the application region and the surface temperature before application, and the application condition of the wax on the member to be applied. A theoretical formula deriving step S13 for deriving a theoretical formula showing the relationship between the temperature difference between the back surface temperature and the surface temperature before coating and the coating thickness of the wax, and the actual application of the wax from the actual temperature difference using the theoretical formula. And a coating film thickness evaluation step S14 for evaluating the film thickness.

In addition, the embodiment further includes an allowable lower limit setting step S15 for setting an allowable lower limit value of the temperature difference corresponding to the allowable lower limit value of the coating film thickness based on the theoretical formula obtained in the theoretical formula deriving step S13. As the evaluation result obtained in the coating film thickness evaluation step S14, only the region where the actual temperature difference obtained by imaging with the infrared thermograph is equal to or larger than the allowable lower limit value of the temperature difference can be visually recognized by the wax coating operator. It further includes an evaluation result display step S16 for displaying on a monitor disposed at a different position. Hereinafter, each process will be described in detail.

(Temperature acquisition process S11)
First, by imaging the coated member with an infrared thermograph, the surface temperature of the coated member before applying the wax and the back surface temperature of the coated region of the wax after the wax has been applied for a certain period of time. get. More specifically, as shown in FIG. 2, the side door 3 and the back door 4 and the hood 5 to be coated with wax can be individually imaged on the coating work station 2 of the vehicle body 1 as a member to be coated. A plurality of infrared thermographs 6 are installed, and the same number of monitors 7 as the infrared thermographs 6 are installed. In this embodiment, as shown in FIG. 2, a position where the coating worker 8 who performs the wax coating work can visually recognize the evaluation result of the coating film thickness of the coating target (such as the side door 3) in charge. The monitor 7 is installed in the direction.

When the vehicle body 1 is actually carried into a predetermined position (application work position) of the application work station 2, first, the corresponding infrared thermograph 6 is opened with the side door 3, the back door 4, and the hood 5 opened. Then, the surfaces of the side door 3, the back door 4, and the hood 5 are imaged, and the surface temperature _TP1 before applying the wax is measured. In this embodiment, as shown in FIG. 2, on the outer surface of the outer side of the side door 3 or the like, a region where the wax is to be applied (in FIG. 5A and FIG. 5B, the wax is actually applied). Imaging by the infrared thermograph 6 is performed so that the region 9) is included in the imaging range, and thereby the temperature (distribution) of the imaging region is measured.

When the surface temperature (distribution) before applying the wax is measured in this way, a plurality of application workers 8 move in front of the side door 3, the back door 4 and the hood 5 to be applied. The rust preventive wax is sprayed and applied to the bag structure 11 of each application target (side door 3, back door 4, hood 5) with an application gun 10 held in hand. The side door 3 will be described in detail by taking the side door 3 as an example. As shown in FIG. 3, the bag structure portion 11 of the side door 3 is in a state in which, for example, the overlapping portion of the outer panel 12 and the inner panel 13 is filled with the adhesive 14. Thus, the outer panel 12 and the inner panel 13 are integrated by folding back (performing a hemming process) the outer peripheral portion of the outer panel 12. Then, the application worker 8 inserts the application gun 10 through a gap provided around the bag structure 11 and applies the inner surface of the outer panel 12 constituting the bag structure 11 and the inner surface of the inner panel 13. Wax 15 is applied to the surface.

Then, after the operation of applying the wax 15 is completed, the back surface of the wax application region 9 (see FIG. 5A and the like) is imaged again with the infrared thermograph 6, and the back surface temperature _TP2 of the application region 9 is measured. In this embodiment, since the relative position between the vehicle body 1 and the infrared thermograph 6 is constant, the wax application region 9 is the imaging range on the outer surface of the outer side such as the side door 3 as before application. As shown in FIG. 3, the infrared thermograph 6 is used for imaging, thereby measuring the temperature (distribution) of the imaging region.

(Actual temperature difference calculation step S12)
Is then calculated as the backside temperature T _P2 of coating region 9 obtained in the temperature measurement step S11, the actual temperature difference T _R of the surface temperature T _P1 before coating. Usually, since the object to be coated the surface temperature of the coated member (side door 3, etc.) by a coating of wax 15 is increased, the actual temperature difference T _R is represented by the following equation.
Formula 1: T _R = T _P2 −T _P1

(Theoretical formula derivation step S13)
In setting the allowable lower limit value _TL of the temperature difference, which will be described later, first, in the present embodiment, based on the application conditions of the wax 15 on the side door 3 and the like, the back surface temperature _TP2 of the application region 9 and before application The theoretical formula showing the relationship between the temperature difference T from the surface temperature T _P1 of the film and the coating film thickness t _WAX of the wax 15 is derived. Here, it is assumed that heat exchange is performed only between the applied wax 15 and the steel plate constituting the side door 3 as the member to be applied (all the heat of the wax 15 is transferred to the steel plate). Then, a theoretical formula showing the relationship between the temperature difference T and the coating thickness t _WAX is derived. Here, the amount of heat C _P required to raise the outer panel 12 by the temperature difference T min is expressed by Equation 2 below.
Formula 2: C _P = c _P × M _P × T
However, c _P is the specific heat of the outer panel, M _P represents the mass of the outer panel in the wax coating region 9.
In this case, the amount of heat C _WAX lost by the applied wax 15 is expressed by the following formula 3.
Formula 3: _CWAX = _cWAX * _MWAX * { _TWAX- ( _TP1 + T)}
Where c _WAX is the specific heat of the wax, M _WAX is the mass of the applied wax, and T _WAX is the temperature of the wax immediately after application.
Further, the mass M _{P of} the outer panel and the mass M _WAX of the wax are respectively
Formula 4: M _P = A × t _P × ρ _P
Formula 5: M _WAX = A × t _WAX × ρ _WAX
It is represented by However, A is a wax coating area, t _P is a thickness of the outer panel, t _WAX is a wax coating thickness, ρ _P is an outer panel density, and ρ _WAX is a wax density.
Then, in Equation 1 and Equation 2, when C _P = C _WAX , the coating thickness t _{WAX of the} wax is expressed as a function of the temperature difference T: Equation 6: t _WAX = {C _P × t _P × ρ _P × T } / [C _WAX × ρ _WAX × {T _WAX − (T _P1 + T)}]
It is expressed as

If the theoretical formula between the temperature difference T and the coating film thickness t _WAX is derived more strictly, the thermal equilibrium formula may be constructed in consideration of the amount of heat diffusing from the wax 15 into the air, for example. However, this time, as long as the allowable lower limit value of the coating film thickness _tWAX can be ensured as described above, a theoretical formula that can be derived under simpler conditions is adopted. As described later, if the allowable lower limit actual temperature difference than the value of the temperature difference derived in case of the absence of thermal diffusion into the air (actual temperature difference T _R) is large, the actual wax 15 applied Since the film thickness t _WAX is even larger, there is no problem in terms of quality assurance.

(Allowable lower limit setting step S15)
In this way, when seeking a theoretical expression of the temperature difference T and the coating thickness t _WAX, based on the theoretical expression, the theory of the allowable lower limit T _L of the temperature difference corresponding to the allowable lower limit t _L of the coating film thickness A value is calculated, and an increase in the temperature of the non-application area 16 due to heat transfer from the wax application area 9 to the non-application area 16 (see FIG. 5A, etc.) is added to this theoretical value, and an allowable lower limit value of the temperature difference _TL is calculated. FIG. 4 is a graph showing the relationship between the temperature difference T and the coating film thickness _t.sub.WAX , in which the curve indicated by the alternate long and short dash line is a theoretical formula showing the relationship between the temperature difference T and the coating film thickness _t.sub.WAX. The plots are values obtained by actually measuring the temperature difference T and the coating film thickness t _WAX . The actual coating thickness of the wax can be measured using, for example, a wet gauge. From this figure, by using a theoretical formula indicating the relationship between the temperature difference T and the coating thickness t _WAX, validity of evaluating the application range of the wax 15 from the measured value of the temperature difference (actual temperature difference T _R) is Proved. Accordingly, for example, a theoretical value of the allowable lower limit value T _L of the temperature difference corresponding to the allowable lower limit value t _L of the coating film thickness, which is a standard value, is calculated from the theoretical formula shown in Formula 6, and the wax coating is applied to the theoretical value. The temperature increase in the non-application area 16 due to heat transfer from the area 9 to the non-application area 16 is added to calculate the allowable lower limit value _TL of the temperature difference. Further, in this embodiment, the allowable lower limit T of the temperature difference is further considered in consideration of the temperature decrease of the application region 9 with the passage of a certain time (here, the application work time of the wax 15) after the application of the wax 15. Set _L.

In addition, the calculation method for the temperature increase in the non-application region 16 due to heat transfer from the wax application region 9 to the non-application region 16 is not particularly limited. For example, the actually applied wax 15 or the steel plate serving as the heat transfer medium You may obtain | require by the calculation based on the physical-property value relevant to heat transfer, or the trial and error by actually apply | coating the wax 15 to the outer panel 12 and measuring temperature. Alternatively, the correlation between the application region and the application amount and the temperature increase may be acquired, and the temperature increase may be calculated based on the acquired correlation. The same applies to the calculation method of the temperature drop in the application region 9 with the passage of a certain time after the application of the wax 15.

(Coating thickness evaluation process S14)
In this way, when calculating the permissible lower limit T _L of the temperature difference, based on the actual temperature difference T _R determined above, the allowable lower limit value T _L of the temperature difference determined immediately before coating thickness of the wax 15 To evaluate. Specifically, it is determined the actual temperature difference T _R is the allowable lower limit value T _L greater than or equal is a region of the temperature difference, as the wax 15 having actually required coating film thickness has been applied. On the other hand, the actual temperature difference T _R is the region is less than the allowable lower limit value T _L of the temperature difference, the wax 15 is not applied, or even have a sufficient coating thickness as has been applied Judge that there is no.

(Evaluation result display step S16)
Then, as the evaluation results obtained with coating thickness evaluation step S14, the actual temperature difference T _R obtained by imaging by the infrared thermograph 6, only the area allowed is the lower limit T _L above temperature difference, the wax 15 Is displayed on a monitor 7 disposed at a position (see FIG. 2) that is visible to the coating operator 8. As a result, only the range in which the wax 15 is actually properly applied is displayed on the monitor 7. Therefore, when the application operator 8 looks at the display content of the monitor 7 and determines that all the areas to be originally applied are displayed, for example, as shown in FIG. 5A or 5B, the wax 15 is appropriate. The coating operation is terminated as being applied to the vehicle body, and the vehicle body 1 is conveyed to the next step. Although illustration is omitted, when a portion that is not displayed in a part of the region to be originally applied is found, the confirmed application operator 8 directly applies the wax 15 to the corresponding location with the application gun 10. Reapply. If necessary, the temperature of the back surface of the coating region 9 is measured again with the infrared thermograph 6 after the coating is completed, and the steps S12 to S16 are repeated to re-apply the coating range. An evaluation may be performed.

Thus, in the present invention, the surface temperature _TP1 of the side door 3 and the like before the wax 15 is applied, and a certain time (here, the time from the start to the end of the wax application operation) after the wax 15 is applied. having applied thickness t _wAX based on the actual temperature difference T _R between the back surface temperature T _P2 of the coating region of the wax after passage so as to evaluate the temperature measurement of once around the wax 15 is applied (imaging) working Accordingly, the application range of the wax 15 can be evaluated. As a result, the time required for the temperature measurement operation can be shortened as compared with the evaluation method using the conventional infrared thermograph that needs to continuously capture images immediately after application. In addition, since the wax coating film thickness _tWAX can be evaluated based on the surface temperature _TP1 of the side door 3 or the like before the wax 15 is applied, it is not affected by the temperature variation of each member to be coated. The evaluation result of the stable application range can be obtained. Further, since it is sufficient to measure only the surface temperature _TP1 of the side door 3 and the like before applying the wax 15 and the back surface temperature _TP2 of the application region 9 after a predetermined time has elapsed after application, the measurement operation itself is nondestructive. And can be implemented in a short time. Therefore, it is possible to evaluate the total number of coating film thicknesses t _WAX without causing a special increase in work time, and it is possible to further improve the quality assurance function.

In the present invention, when setting the allowable lower limit value _TL of the temperature difference, not only the temperature rise of the application region 9 due to the application of the wax 15 but also the heat transfer from the wax application region 9 to the non-application region 16 is performed. The allowable lower limit value _TL of the temperature difference is set in consideration of the temperature rise in the non-application area 16. Here, for example, when the allowable lower limit value _TL of the temperature difference is set from the theoretical formula without considering the temperature increase in the non-application area 16 due to the heat transfer, the value takes into account the temperature increase in the non-application area 16. It becomes small compared with the case. Therefore, for example, if an image is taken immediately after application, a display result of the monitor 7 that reflects the actual application area 9 can be obtained. After a certain period of time (for example, wax 15 application operation time), as shown in FIG. In addition, even portions that are not actually applied are colored on the monitor 7 (in the gray scale in the figure, the closer to white, the higher the temperature, and the closer to black, the lower the temperature). The same applies to FIG. 5B, FIG. 7A, and FIG. 7B.) And an accurate application range cannot be displayed. On the other hand, if the allowable lower limit value _TL of the temperature difference is set by taking into account the temperature rise of the non-application area 16 due to heat transfer from the application area 9 as in the present invention, the wax 15 is properly applied. It is possible to avoid a situation in which it is erroneously determined that the non-applied area is the application area. In addition, when the application work of the wax 15 is prolonged or completed in a short time, the elapsed time from the start of application to imaging changes, and thus the actually obtained temperature distribution varies (FIG. 5A and FIG. 5). 5B), since the evaluation is performed in consideration of the temperature increase due to the heat transfer to the non-application area 16 as described above, there is no great difference in the display area. Therefore, with this evaluation method, it is possible to evaluate the application range of the wax 15 with high accuracy while giving some elasticity to the time from the start of application to the temperature measurement operation. Moreover, it becomes possible to improve the reliability with respect to the evaluation result.

By the way, in the region 9 where the wax 15 is applied, the temperature rises due to heat transfer from the wax 15, but after a certain period of time, the amount of heat transfer (heat diffusion) to the surroundings is the amount of heat transfer from the wax 15. Can happen. Therefore, if the allowable lower limit value _TL for the temperature difference is set to be larger than necessary, for example, as shown in FIG. Although it can be evaluated, after a further time has passed, the temperature starts to drop in a part of the application region 9, as shown in FIG. 7B, although it is a region where the wax 15 is properly applied, There is a risk that it is not displayed on the monitor 7 (determined as the non-application area 16). In this regard, as described above, after the application of the wax 15, the allowable lower limit value _TL of the temperature difference is set by further taking into account the temperature drop of the application region with the passage of a certain time (ie, the time from the start of application to the start of imaging). By setting, as shown in FIG. 5B, substantially the same display result (display range) can be obtained even after a certain time has passed since the end of the coating operation.

Of course, the method for evaluating the coating thickness of the wax according to the first aspect of the present invention can adopt any configuration without departing from the spirit of the present invention. For example, in the above-described embodiment, in the temperature acquisition step S11, the surface temperature _TP1 of the side door 3 and the like before the wax 15 is applied is set to the non-application area, that is, the area where the wax 15 is not applied including the application scheduled area. a case has been exemplified to obtain the surface temperature T _P1, of course, also possible to obtain the surface temperature T _P1 in the non-application area 16 excluding the coating region where, as the surface temperature T _P1 in the area where wax 15 is not applied It is. In this case, for example, a little away area from the application area 9 of the coated member of the side door 3 or the like by imaging with an infrared thermographic 6, it is possible to obtain the surface temperature T _P1 in the area. In addition, since the region where the temperature change due to the application of the wax 15 is extremely small is set as the non-application region, the acquisition timing is not particularly limited. For example, the acquisition may be performed by imaging during the application operation.

Further, in the above embodiment, the surface temperature _{TP1 of the} region to which the wax 15 is not applied of the member to be coated (such as the side door 3), and the wax application region after a predetermined time has elapsed after the wax 15 is applied. 9 of the backside temperature T _P2 acquired once each has been to evaluate the coating thickness t _WAX based on the actual temperature difference T _R at this time, of course not limited to this embodiment. For example, immediately after the start of the application of the wax 15, a thermal image (temperature distribution image) is continuously captured by the infrared thermograph 6, and arithmetic processing for sequentially evaluating the above-described coating film thickness T _{WAX for} the captured thermal image. performed (comparison between the actual temperature difference T _R at the time of image acquisition and allowable lower limit value T _L), may be continuously display the result on the monitor 7. That is, as the coating work of the wax 15 is started, steps up to the step S11 ~ S16 (in particular, comparison between the acquisition and the allowable lower limit value T _L of the temperature distribution of the actual temperature difference T _R which changes from moment to moment) Repeat The evaluation result may be displayed on the monitor 7. As a result, the wax 15 is sequentially displayed on the monitor 7 from a region where the wax 15 is applied to an appropriate film thickness as the worker applies the wax 15. In this case, the surface temperature _TP1 of the non-application area may be any of the surface temperature before applying the wax 15 and the area (non-application area 16) excluding the area where the wax 15 is to be applied (the latter). If can be updated on the basis of sequential latest thermal image or the thermal image which has been acquired immediately also the surface temperature T _P1 acquired.), also, based on the actual temperature difference T _R are sequentially acquired in this way The evaluation result of the coating film thickness may be continuously displayed on the monitor 7.

Moreover, although the case where the total number evaluation was assumed was illustrated in the above description, the coating film thickness evaluation method for the wax according to the first aspect of the present invention has a ratio of one unit to a plurality of units (for example, three units). Of course, it may be evaluated, or may be evaluated at a rate of once every predetermined time (for example, 1 hour).

Hereinafter, an embodiment of a wax application range evaluation method according to the second aspect of the present invention will be described with reference to the drawings. In this embodiment, the case where the application range of the wax applied to the door of the vehicle body and the bag structure portion of the hood is evaluated will be described as an example.

FIG. 8 shows a flowchart of the wax coating area evaluation method according to an embodiment of the second aspect of the present invention. As shown in FIG. 8, in this evaluation method, the surface temperature of the member to be coated before applying the wax, and the back surface temperature of the wax application region after the wax has been applied for a certain period of time are applied. Temperature acquisition step S21 acquired by imaging the member with an infrared thermograph, actual temperature difference calculation step S22 for calculating the actual temperature difference between the back surface temperature of the application region and the surface temperature before application, and direct application of wax Taking into account the temperature rise due to heat transfer and the temperature rise in the non-application area due to heat transfer from the wax application area to the non-application area, the allowable lower limit of the temperature difference between the back surface temperature of the application area and the surface temperature before application is set. An allowable lower limit setting step S23 to be set, and an application range evaluation step S24 for evaluating the application range of the wax based on the actual temperature difference and the allowable lower limit value of the temperature difference are provided.

In this embodiment, before the allowable lower limit setting step S23, the temperature difference between the back surface temperature of the coating region and the surface temperature before coating, and the wax coating film based on the wax coating conditions for the member to be coated. Further, a theoretical formula deriving step S25 for deriving a theoretical formula indicating the relationship with the thickness is further provided, and as an evaluation result obtained in the coating range evaluating step S24, an actual temperature difference obtained by imaging with an infrared thermograph is a temperature. It further includes an evaluation result display step S26 for displaying only a region that is equal to or larger than the allowable lower limit value of the difference on a monitor disposed at a position that is visible to the wax application worker. Hereinafter, each process will be described in detail.

(Temperature acquisition process S21)
First, by imaging the coated member with an infrared thermograph, the surface temperature of the coated member before applying the wax and the back surface temperature of the coated region of the wax after the wax has been applied for a certain period of time. get. More specifically, as shown in FIG. 2, the side door 3 and the back door 4 and the hood 5 to be coated with wax can be individually imaged on the coating work station 2 of the vehicle body 1 as a member to be coated. A plurality of infrared thermographs 6 are installed, and the same number of monitors 7 as the infrared thermographs 6 are installed. In this embodiment, as shown in FIG. 2, the position and direction in which the application worker 8 who performs the wax application operation can visually recognize the evaluation result of the application range of the application target (such as the side door 3) at the operation position. In addition, a monitor 7 is installed.

(Actual temperature difference calculation step S22)
Then, the backside temperature T _P2 of coating region 9 obtained in the temperature measurement step S21, the actual temperature difference T _R of the surface temperature T _P1 before coating, is calculated based on the equation 1 described above. As a calculation method, for example, a method based on the above-described formula 1 can be given.

(Theoretical formula derivation step S25)
In setting the allowable lower limit value _TL of the temperature difference, which will be described later, first, in the present embodiment, based on the application conditions of the wax 15 on the side door 3 and the like, the back surface temperature _TP2 of the application region 9 and before application The theoretical formula showing the relationship between the temperature difference T from the surface temperature T _P1 of the film and the coating film thickness t _WAX of the wax 15 is derived. Here, it is assumed that heat exchange is performed only between the applied wax 15 and the steel plate constituting the side door 3 as the member to be applied (all the heat of the wax 15 is transferred to the steel plate). Then, theoretical formulas (for example, the above-described formulas 2 to 6) showing the relationship between the temperature difference T and the coating film thickness t _WAX are derived. Thereby, the coating film thickness _tWAX of the wax can be displayed as a function of the temperature difference T.

If the theoretical formula between the temperature difference T and the coating film thickness t _WAX is derived more strictly, the thermal equilibrium formula may be constructed in consideration of the amount of heat diffusing from the wax 15 into the air, for example. However, this time, as long as the allowable lower limit value of the coating film thickness _tWAX can be ensured as described above, a theoretical formula that can be derived under simpler conditions is adopted. As described later, if the allowable lower limit value T actual temperature difference than the _L temperature difference derived in case of the absence of thermal diffusion into the air (actual temperature difference T _R) is large, the actual wax 15 Since the coating film thickness t _WAX of the coating film shows a larger value, there is no problem in terms of quality assurance.

(Allowable lower limit setting step S23)
In this way, when seeking a theoretical expression of the temperature difference T and the coating thickness t _WAX, based on the theoretical expression, the theory of the allowable lower limit T _L of the temperature difference corresponding to the allowable lower limit t _L of the coating film thickness A value is calculated (see FIG. 4), and this theoretical value is added to the temperature increase in the non-application area 16 due to heat transfer from the wax application area 9 to the non-application area 16 (see FIG. 5A, etc.) An allowable lower limit value _TL of the temperature difference is calculated. Here, as shown in FIG. 4, the application range of the wax 15 is evaluated from the measured value of the temperature difference (actual temperature difference T _R ) using a theoretical formula showing the relationship between the temperature difference T and the coating film thickness t _WAX. Therefore, for example, the theoretical value of the allowable lower limit value T _L of the temperature difference corresponding to the allowable lower limit value t _L of the coating film thickness that is the standard value is calculated from the theoretical formula shown in Equation 6. Then, the temperature rise in the non-application area 16 due to heat transfer from the wax application area 9 to the non-application area 16 is added to the theoretical value to calculate the allowable lower limit value _TL of the temperature difference. Further, in this embodiment, the allowable lower limit T of the temperature difference is further considered in consideration of the temperature decrease of the application region 9 with the passage of a certain time (here, the application work time of the wax 15) after the application of the wax 15. Set _L.

In addition, the calculation method for the temperature increase in the non-application area 16 due to heat transfer from the wax application area 9 to the non-application area 16 is not particularly limited. For example, the actually applied wax 15 or a steel plate serving as a heat transfer medium. It may be obtained by calculation based on physical property values related to the heat transfer of the above or by trial and error by actually applying the wax 15 to the outer panel 12 and measuring the temperature. Alternatively, the correlation between the application region and the application amount and the temperature increase may be acquired, and the temperature increase may be calculated based on the acquired correlation. The same applies to the calculation method of the temperature drop in the application region 9 with the passage of a certain time after the application of the wax 15.

(Application range evaluation process S24)
In this way, when calculating the permissible lower limit T _L of the temperature difference, and the actual temperature difference T _R determined above, based on the allowable lower limit value T _L of the temperature difference determined immediately before the application range of the wax 15 evaluate. Specifically, it is determined the actual temperature difference T _R is the allowable lower limit value T _L greater than or equal is a region of the temperature difference, as the wax 15 having actually required coating film thickness has been applied. On the other hand, the actual temperature difference T _R is the region is less than the allowable lower limit value T _L of the temperature difference, the wax 15 is not applied, or even have a sufficient coating thickness as has been applied Judge that there is no.

(Evaluation result display step S26)
Then, as the evaluation results obtained in the application range evaluation step S24, the actual temperature difference T _R obtained by imaging by the infrared thermograph 6, only the area allowed is the lower limit T _L above temperature difference, the wax 15 The information is displayed on a monitor 7 disposed at a position (see FIG. 2) that can be visually recognized by the application worker 8. As a result, only the range in which the wax 15 is actually properly applied is displayed on the monitor 7. Therefore, when the application operator 8 looks at the display content of the monitor 7 and determines that all the areas to be originally applied are displayed, for example, as shown in FIG. 5A or 5B, the wax 15 is appropriate. The coating operation is terminated as being applied to the vehicle body, and the vehicle body 1 is conveyed to the next step. Although illustration is omitted, when a portion that is not displayed in a part of the region to be originally applied is found, the confirmed application operator 8 directly applies the wax 15 to the corresponding location with the application gun 10. Reapply. If deemed necessary, the temperature of the back surface of the coating region 9 is measured again with the infrared thermograph 6 after the coating is completed, and the steps S22 to S26 are repeated to re-apply the coating range. An evaluation may be performed.

In the present invention, when setting the allowable lower limit value _TL of the temperature difference, not only the temperature rise of the application region 9 due to the application of the wax 15 but also the heat transfer from the wax application region 9 to the non-application region 16 is performed. The allowable lower limit value _TL of the temperature difference is set in consideration of the temperature rise in the non-application area 16. Here, for example, when the allowable lower limit value _TL of the temperature difference is set from the theoretical formula without considering the temperature increase in the non-application area 16 due to the heat transfer, the value takes into account the temperature increase in the non-application area 16. It becomes small compared with the case. Therefore, for example, if an image is taken immediately after application, a monitor display result that reflects the actual application area 9 can be obtained. After a certain period of time (for example, wax application operation time), as illustrated in FIG. Even portions that are not actually applied are colored and displayed on the monitor, and an accurate application range cannot be displayed. On the other hand, if the allowable lower limit value _TL of the temperature difference is set by taking into account the temperature rise of the non-application area 16 due to heat transfer from the application area 9 as in the present invention, the wax 15 is properly applied. It is possible to avoid a situation in which it is erroneously determined that an unapplied area is an application area. In addition, when the application work of the wax 15 is prolonged or completed in a short time, the elapsed time from the start of application to imaging changes, and thus the actually obtained temperature distribution varies (FIG. 5A and FIG. 5). 5B), since the evaluation is performed in consideration of the temperature increase due to the heat transfer to the non-application area 16 as described above, there is no great difference in the display area. Therefore, with this evaluation method, it is possible to evaluate the application range of the wax 15 with high accuracy while giving some elasticity to the time from the start of application to the temperature measurement operation. Moreover, it becomes possible to improve the reliability with respect to the evaluation result.

By the way, in the region 9 where the wax is applied, the temperature rises due to heat transfer from the wax 15, but after a certain period of time, the amount of heat transfer (heat diffusion) to the surroundings becomes the amount of heat transfer from the wax 15. A situation can be exceeded. Therefore, if the allowable lower limit value _TL for the temperature difference is set to be larger than necessary, for example, as shown in FIG. Although it can be evaluated, after a further time has passed, the temperature starts to drop in a part of the application region 9, as shown in FIG. 7B, although it is a region where the wax 15 is properly applied, There is a possibility that it is not displayed (determined as the non-application area 16). In this regard, as described above, after the application of the wax 15, the allowable lower limit value _TL of the temperature difference is set by further taking into account the temperature drop of the application region with the passage of a certain time (ie, the time from the start of application to the start of imaging). By setting, as shown in FIG. 5B, substantially the same display result (display range) can be obtained even after a certain time has passed since the end of the coating operation.

Of course, the wax application range evaluation method according to the second aspect of the present invention can take any configuration without departing from the spirit of the present invention. For example, in the above-described embodiment, in the temperature acquisition step S21, the surface temperature _TP1 of the side door 3 or the like before the wax 15 is applied is set to the non-application area, that is, the area where the wax 15 is not applied including the application scheduled area. a case has been exemplified to obtain the surface temperature T _P1, of course, also possible to obtain the surface temperature T _P1 in the non-application area 16 excluding the coating region where, as the surface temperature T _P1 in the area where wax 15 is not applied It is. In this case, for example, a region away from the application area 9 of the coated member of the side door 3 or the like by imaging with an infrared thermographic 6, it is possible to obtain the surface temperature T _P1 in the area. In addition, since the region where the temperature change due to the application of the wax 15 is extremely small is set as the non-application region, the acquisition timing is not particularly limited. For example, the acquisition may be performed by imaging during the application operation.

Further, in the above embodiment, the surface temperature _{TP1 of the} region to which the wax 15 is not applied of the member to be coated (such as the side door 3), and the wax application region after a predetermined time has elapsed after the wax 15 is applied. 9 of the backside temperature T _P2 acquired once each has been to evaluate the application range based on the actual temperature difference T _R at this time, of course not limited to this embodiment. For example, immediately after the start of the application of the wax 15, the thermal image (temperature distribution image) by the infrared thermograph 6 is continuously captured, and the above-described calculation processing (image acquisition) for the application range is sequentially evaluated for the captured thermal image. compares) between the actual temperature difference T _R and the allowable lower limit T _L of time, may be continuously display the result on the monitor 7. That is, as the coating work of the wax 15 is started, steps up to the step S21 ~ S26 (in particular, comparison between the acquisition and the allowable lower limit value T _L of the temperature distribution of the actual temperature difference T _R which changes from moment to moment) Repeat The evaluation result may be displayed on the monitor 7. As a result, as the wax 15 is applied by the worker, the monitor 15 sequentially displays the area from the area where the wax 15 is properly applied. In this case, the surface temperature _TP1 of the non-application area may be any of the surface temperature before applying the wax 15 and the area (non-application area 16) excluding the area where the wax 15 is to be applied (the latter). If can be updated based on the sequentially most recent thermal image acquired immediately before the thermal image also the surface temperature T _P1 acquired.) the application of this manner based on the actual temperature difference T _R are sequentially acquired The film thickness evaluation result may be continuously displayed on the monitor 7.

Moreover, although the case where the total number evaluation was assumed was illustrated in the above description, the wax coating area evaluation method according to the second aspect of the present invention is evaluated at a ratio of one unit to a plurality of units (for example, three units). Of course, it is also possible to perform evaluation at a rate of once every predetermined time (for example, 1 hour).

Hereinafter, an embodiment of a coating inspection system according to the third aspect of the present invention will be described with reference to the drawings.

As shown in FIG. 2, the coating inspection system according to the present embodiment individually images the side door 3, the back door 4, and the hood 5 to be coated on the coating work station 2 of the vehicle body 1 as a member to be coated. An infrared thermograph 6 that performs the operation and a monitor 7 that is disposed at a position and orientation that can be visually recognized by the application operator 8 and that displays the temperature distribution of the application region acquired by imaging the infrared thermograph 6. The monitor 7 can display the dynamic image 17 and the still image 18 (both refer to FIG. 9A and the like described later) of the temperature distribution.

In the present embodiment, using the above inspection system, a plurality of application workers 8 move in front of the side door 3, back door 4, and hood 5 to be applied, and the application gun 10 held in the hand. Then, the coating state when the rust-preventing wax is sprayed and applied toward the bag structure 11 of each member to be coated (side door 3, back door 4, hood 5) is inspected. Here, taking the side door 3 as an example and explaining the details of the coating operation, as shown in FIG. 3, the bag structure portion 11 of the side door 3 is, for example, an overlapping portion of the outer panel 12 and the inner panel 13. The outer panel 12 and the inner panel 13 are integrated by folding back (performing a hemming process) the outer peripheral portion of the outer panel 12 with the adhesive 14 filled. Then, the application worker 8 inserts the application gun 10 through a gap provided around the bag structure 11 and applies the inner surface of the outer panel 12 constituting the bag structure 11 and the inner surface of the inner panel 13. The wax 15 is applied as a coating.

Further, in the present embodiment, as shown in FIG. 10, the inspection system includes a display instruction unit 20 for instructing display of the still image 18 on the monitor 7 by operation, and a conveying means 23 by operation (see FIG. 2). Further, an operation member 22 provided with a conveyance instructing unit 21 for instructing conveyance of the vehicle body 1 is provided. In the present embodiment, since the above-described series of operations are performed while the vehicle body 1 is being transported, if there is a transport instruction, the transport is continued as it is, and if there is no transport instruction (if there is no operation of the transport instruction unit 21), a predetermined time After the lapse, the vehicle body 1 is stopped. In the present embodiment, the operation of the conveyance instruction unit 21 is controlled to be effective only after the still image 18 is displayed on the monitor 7 by the operation of the display instruction unit 20. Thereby, when the display instruction | indication part 20 and the conveyance instruction | indication part 21 are pushed wrongly, it can avoid the situation where the vehicle body 1 flows into the following process, without receiving the application | coating inspection by the application | coating worker 8. FIG. The operation member 22 having the above-described configuration is attached to, for example, the application gun 10 and is in a state where the application operator 8 who uses the application gun 10 can immediately operate.

FIGS. 9A to 9C show an example of the display form of the monitor 7 as a display unit. When only the dynamic image 17 is displayed (FIG. 9A), the dynamic image 17 and the still image 18 are displayed simultaneously. In some cases, the inspection result 19 is displayed (FIG. 9C). Here, the dynamic image 17 continuously displays the temporal change of the temperature distribution in the application region of the wax 15 obtained by imaging with the infrared thermograph 6, and the still image 18 is the dynamic image 17. The temperature distribution at a predetermined time is displayed.

Further, the temperature distribution displayed as the dynamic image 17 or the still image 18 may be raw data obtained by imaging the target part (part including the application region of the wax 15) with the infrared thermograph 6. In order to make it easier to determine whether or not the wax 15 is properly applied from a more practical viewpoint, the raw data may be subjected to predetermined processing.

Specifically, the evaluation results obtained by the wax coating thickness evaluation method according to the first aspect of the present invention and the wax coating range evaluation method according to the second aspect of the present invention described above are dynamic images. 17 or a static image 18 can be displayed on the monitor 7. Among them, for example in the case of displaying the results obtained in the application range evaluation method on the monitor 7, (1) the surface temperature T _P1 of the application member before applying the wax 15, and began to apply the wax 15 the backside temperature T _P2 of the wax coating region 9 (see FIG. 5A, etc.) after obtains by imaging the object to be coated member with an infrared thermographic 6, the backside temperature T _P2 of the coating area, before coating calculates the actual temperature difference T _R of the surface temperature T _P1 of, in consideration of the temperature rise of the coated area by the application of the wax 15, the surface temperature T _P1 before coating the backside temperature T _P2 of application area 9 to set the allowable lower limit value T _L of the temperature difference T, the actual temperature difference T _R is displayed on the monitor 7 only area allowed is the lower limit T _L or more temperature difference as a dynamic image 17 and the still image 18 It may be. In this case, for example, the evaluation result (temperature distribution) shown in FIGS. 5A to 7B is displayed as a dynamic image 17 or a static image 18 at a predetermined position on the monitor. Moreover, the actual temperature difference T _R becomes as reflecting the latest backside temperature distribution is displayed on dynamic image 17, the still image 18, a display instruction section 20 for instructing the display of the still image 18 applied worker 8 It reflects the backside temperature distribution at the time of operation.

Alternatively, among the evaluation method described above, it is to be displayed to the results obtained in the coating film thickness evaluation method on the monitor 7, and the surface temperature T _P1 of the application member before the applying (2) Wax 15, Wax The back surface temperature T _P2 of the wax application region 9 after starting to apply 15 is acquired by imaging the coated member with the infrared thermograph 6, and the back surface temperature T _P2 of the application region and before application calculates the actual temperature difference T _R of the surface temperature T _P1, based on the coating condition of the wax 15 with respect to the coating member, the temperature difference T between the surface temperature T _P1 before coating the backside temperature T _P2 of application area 9 If, we derive the theoretical formula indicating the relationship between the coating thickness t _wAX wax 15, based on the theoretical formula, the allowable lower limit T _L of the temperature difference corresponding to the allowable lower limit t _L of the coating film thickness set, the actual temperature difference T _R is the temperature It may be displayed on the monitor 7 only area allowed is the lower limit T _L or more difference as a dynamic image 17 and the still image 18. Also in this case, for example, the evaluation result (temperature distribution) shown in FIGS. 5A to 7B is displayed as a dynamic image 17 or a static image 18 at a predetermined position on the monitor. Moreover, the actual temperature difference T _R becomes as reflecting the latest backside temperature distribution is displayed on dynamic image 17, the still image 18, a display instruction section 20 for instructing the display of the still image 18 applied worker 8 It reflects the backside temperature distribution at the time of operation.

Next, an example of an inspection method using the coating inspection system having the above configuration will be described with reference to the drawings.

(S31) Application Work Process First, as shown in FIG. 2, when the vehicle body 1 is carried into a predetermined position (application work position) of the application work station 2, the side door 3, the back door 4, and the hood 5 are opened. In this state, a plurality of application workers 8 move in front of the side door 3, the back door 4, and the hood 5 that are the application targets, and each application member (side door 3) is held by an application gun 10 held in hand. Anti-rust wax 15 is sprayed and applied toward the bag structure 11 of the back door 4 and the hood 5). At this time, in the infrared thermograph 6 corresponding to each member to be coated, the coated region of the wax 15 is included in the imaging range among the outer surfaces of the side door 3, the back door 4, and the hood 5 on the outer side. In addition, imaging with the infrared thermograph 6 is performed, and thereby the temperature distribution in the application region is acquired. Then, the acquired temperature distribution of the application region of the wax 15 is displayed on the monitor 7 as a dynamic image 17 (see FIG. 9A). At this time, for example, the temperature distribution in the same region before application is acquired in advance, and the temperature distribution after performing the processing (1) or (2) is continuously displayed on the monitor 7 as the dynamic image 17. May be displayed.

(S32) Still Image Display Step When the application work of the wax 15 is completed, the application operator 8 operates the display instruction unit 20 of the operation member 22 to stop the temperature distribution on the monitor 7 as shown in FIG. 9B. The image 18 is displayed. In this case, the displayed still image 18 is a temperature distribution in the dynamic image 17 at the time when the display instruction unit 20 is operated. The display mode of the still image 18 at this time is not particularly limited. For example, as shown in FIG. 9B, the still image 18 and the dynamic image 17 may be displayed in a state where they are arranged side by side. Further, the still image 18 may be displayed in a size larger than the dynamic image 17.

(S33) Pass / Fail Judgment Step When the temperature distribution of the application region is displayed as the still image 18 on the monitor 7 in this way, the application operator 8 who actually performed the application operation viewed the monitor 7 and displayed it on the monitor 7. Based on the still image 18, the quality of the application state is determined. That is, if the region showing the predetermined temperature (threshold value) or more in the temperature distribution displayed as the still image 18 includes all the regions where the application was planned, it is determined that the application state is good. Then, the process proceeds to the next (S34) vehicle body conveyance process. Alternatively, when the area indicating the threshold value or more does not include a part of the area where the application is planned, the application state is bad, in other words, the unpainted state (wax 15 is not applied or the application film is not applied). It is determined that there is an area where the thickness is insufficient), and the process proceeds to the repainting step (S35) (FIG. 11). As a display format on the monitor 7, for example, as shown in FIG. 5A to FIG. 7B, an area showing a temperature higher than a threshold value and less than the threshold value so that the coating operator 8 can easily grasp at a glance. It is possible to adopt a method in which the color tone is clearly different from the region showing the temperature.

(S34) Carriage Carrying Step When the coating worker 8 determines that the coating state is good in the quality determination step S33, the coating worker 8 operates the transport instruction unit 21 of the operation member 22 to the transport means 23. The conveyance of the vehicle body 1 is instructed. In the present embodiment, since the above-described series of operations is performed while the vehicle body 1 is being conveyed, the vehicle body 1 is continuously conveyed as it is if there is a conveyance instruction. Thereby, for example, the vehicle body 1 that has been inspected is transferred to the next process by the transfer means 23, and a series of operations and inspections on the vehicle body 1 are completed. The inspection result 19 is displayed on the monitor 7 by the operation of the conveyance instructing unit 21 (for example, “OK” is displayed), and it is confirmed that not only the eight coating workers but also the surrounding workers are in a good coating state. It can be recognized (FIG. 9C).

(S35) Repainting step When the coating operator 8 determines that the application state is poor in the above-described quality determination step, that is, there is an unpainted portion, the coating worker 8 reapplies the wax 15 to the region where the unpainted portion remains. Do (repaint). In this case, after registering an area where there is an unpainted area in the still image 18 used for determination, the wax 15 is sprayed again with the tip (nozzle) of the application gun 10 directed to the corresponding position to apply the corresponding area. Do. At the same time, the wax 15 is applied to the unapplied area while confirming whether the dynamic image 17 has been properly repainted. When the repainting operation is completed in this manner, the display instruction unit 20 of the still image 18 is operated again, the temperature distribution at the end of the repainting operation is displayed again as the still image 18, the quality is determined, and the determination result is good The above steps (S32, S33, S35) are repeated until appears. The operation of the transport instruction unit 21 is not performed, and the vehicle body 1 stops when an allowable application work time has elapsed, and a warning sound or the like is generated. Further, the monitor 7 displays an inspection result 19 indicating that the coating is defective (for example, “NG” is displayed), and the surrounding workers including the eight coating workers can recognize that the coating is defective. .

As described above, in the present invention, since the monitor 7 for displaying the temperature distribution of the application region acquired by the imaging of the infrared thermograph 6 is provided in the range that the application operator 8 can visually recognize, the application operator 8 itself The state of application can be confirmed and an inspection regarding the quality of the application operation can be performed. At this time, the monitor 7 can display a dynamic image 17 that continuously displays the change over time in the temperature distribution of the application region, so that the temperature distribution of the member to be applied can be displayed while the application operator 8 is working. The coating operation can be performed while watching. Therefore, the coating operation can be performed smoothly. Further, since the still image 18 at a predetermined time of the dynamic image 17 can be displayed on the monitor 7, for example, the still image 18 at the end of the application operation, that is, the temperature distribution of the application region immediately after the application operation is completed is in a static state. Can be confirmed. As a result, the quality of the application state can be checked in detail and accurately, so that it is possible to quickly and accurately determine the presence or absence of unpainted areas, and the application operator 8 himself can quickly and accurately also in areas where repainting is necessary. I can grasp it. Of course, it is possible to check the repaint quality in detail by newly displaying the still image 18 at the end of each repainting operation. Therefore, not only the initial coating operation but also the repainting inspection can be performed quickly and accurately.

In the present embodiment, the dynamic image 17 and the still image 18 regarding the temperature distribution in the application region are simultaneously displayed on one monitor 7 (FIGS. 9B and 9C). After the still image 18 at the time is displayed on the monitor 7, the temporal change of the temperature distribution after the acquisition of the still image 18 is continuously displayed on the dynamic image 17. Thus, after the necessity of repainting is performed based on the still image 18 as described above, the coating operation is performed while comparing the still image 18 with the dynamic image 17 reflecting the intermediate result of the subsequent repainting operation. Can do. Therefore, it is possible to perform the coating operation while confirming in real time the region that has already been repainted and the region that still needs repainting, and the repainting operation can be performed smoothly and quickly.

Further, in the present embodiment, a display instruction unit 20 that instructs the display of the still image 18 on the monitor 7 by operation and a conveyance instruction unit 21 that instructs the conveyance of the vehicle body 1 by the conveyance unit 23 by operation are further provided. Therefore, after the application operator 8 finishes the application operation, the temperature distribution after the application operation is completed is displayed on the monitor 7 as a still image 18 by operating the display instruction unit 20. Then, when the coating worker 8 himself / herself determines whether the coating operation is good or not and determines that there is no problem (there is no unpainted), the transport instruction unit 21 is operated to transport the vehicle body 1 having the member to be coated. 23 can be continued. On the other hand, if the application worker 8 determines that there is a problem (there is an unpainted area) as a result of determining whether the application operation is good or not using the still image 18, the operation until the predetermined time elapses unless the conveyance instruction unit 21 is operated. The repainting operation can be performed without stopping the vehicle body 1. In addition, it is possible to transport the corresponding vehicle body 1 without stopping by operating the transport instructing unit 21 when the coating operator 8 determines that the unpainted portion disappears and can be transported to the next process by the repainting operation. . As described above, it is possible to perform a series of these inspections and transport operations quickly and reliably with respect to the total number.

In the present embodiment, the monitor 7 as a display unit is disposed above the vehicle body 1 flowing on the coating work station 2. As shown in FIG. 1, this type of coating operation is normally performed on the production line of the vehicle body 1 that is a member to be coated, and a plurality of coating workers 8 perform a plurality of sites of coating work simultaneously. Therefore, if the monitor 7 is disposed just to the side of the coating work station 2, the other workers including the coating worker 8 in other parts and the surrounding facilities block the field of view, so In some cases, the temperature distribution cannot be confirmed. In this respect, in the present embodiment, the monitor 7 is disposed above the vehicle body 1 and in the direction of the application worker 8 who is in charge of each application site, so this type of problem is avoided as much as possible. The visibility of the corresponding application worker 8 can be improved.

As mentioned above, although one Embodiment of the application | coating inspection system which concerns on the 3rd side surface of this invention was described, this invention can also take a structure other than the above, unless it deviates from the structure reflecting the intention. .

For example, in the above-described embodiment, the case where the operation member 22 provided with the display instruction unit 20 and the conveyance instruction unit 21 is mounted on the coating gun 10 is illustrated, but the present invention is not limited to this mode. For example, the display instruction unit 20 and the conveyance instruction unit 21 may be arranged within the reach of the application worker 8 during the application operation, such as equipment installed near the work area or the application operator 8 himself / herself. That's fine. Alternatively, the display instruction unit 20 and the conveyance instruction unit 21 may also be used as an injection switch (lever) of the application gun 10. In this case, the operation of turning off the injection switch after the application work is completed functions as a display trigger for the still image 18. The subsequent temperature operation of the injection switch functions as a display trigger for the dynamic image 17 or an imaging acquisition trigger for the infrared thermograph 6.

In the above embodiment, the case where the application work is performed while the vehicle body 1 is being transported is taken as an example. Of course, the application work is performed with the vehicle body 1 introduced onto the application work station 2 temporarily stopped, As a result of the inspection (good / bad determination) by the coating worker 8 itself, it may be determined that there is no unpainted area, and the conveyance instruction unit 21 may be operated to control the conveyance of the vehicle body 1 to be resumed.

DESCRIPTION OF SYMBOLS 1 Car body 2 Application | coating work station 3 Side door 4 Back door 5 Hood 6 Infrared thermograph 7 Monitor 8 Application worker 9 Application area 10 Application gun 11 Bag structure part 12 Outer panel 13 Inner panel 14 Adhesive 15 Wax 16 Non-application area 17 Movement Target image 18 still image 19 inspection result 20 display instruction unit 21 conveyance instruction unit 22 operation member 23 conveyance means

Claims

A temperature acquisition step of acquiring the surface temperature of a non-application region where the wax is not applied among the members to be coated and the back surface temperature of the region where the wax is applied by imaging the member to be coated with an infrared thermograph; ,
An actual temperature difference calculating step of calculating an actual temperature difference between the back surface temperature of the application region and the surface temperature of the non-application region;
Based on the application condition of the wax to the application member, a theoretical formula indicating the relationship between the temperature difference between the back surface temperature of the application area and the surface temperature of the non-application area and the applied film thickness of the wax is derived. The theoretical formula derivation process,
A method for evaluating a coating thickness of a wax, comprising: a coating thickness evaluation step for evaluating an actual coating thickness of the wax from the actual temperature difference using the theoretical formula.
The surface temperature of the non-application area where the wax is not applied among the members to be applied and the back surface temperature of the application area of the wax after a predetermined time has passed since the wax was applied. A temperature acquisition step to acquire by imaging with a graph;
An actual temperature difference calculating step of calculating an actual temperature difference between the back surface temperature of the application region and the surface temperature of the non-application region;
In consideration of the temperature increase of the application region due to the application of the wax, an allowable lower limit value setting step of setting an allowable lower limit value of a temperature difference between the back surface temperature of the application region and the surface temperature of the non-application region;
Based on the actual temperature difference and an allowable lower limit value of the temperature difference, comprising an application range evaluation step of evaluating the application range of the wax,
In the allowable lower limit setting step, the wax application range evaluation method for setting the allowable lower limit of the temperature difference in consideration of the temperature increase of the non-application area due to heat transfer from the wax application area to the non-application area .
The method for evaluating a coating thickness of a wax according to claim 1 or 2, wherein, in the temperature acquisition step, a surface temperature of the member to be coated before applying the wax is acquired as a surface temperature of the non-application region.
3. The method for evaluating a coating thickness of a wax according to claim 1 or 2, wherein, in the temperature acquisition step, a surface temperature of the member to be coated excluding a region where the wax is scheduled to be applied is acquired as a surface temperature of the non-application region.
Based on the theoretical formula, further comprising an allowable lower limit setting step of setting an allowable lower limit of the temperature difference corresponding to the allowable lower limit of the coating film thickness,
In the coating film thickness evaluation step, the actual temperature difference obtained by imaging with an infrared thermograph calculates a region that is equal to or greater than the allowable lower limit value of the temperature difference, and only a region that is equal to or greater than the allowable lower limit value. The method for evaluating a coating thickness of a wax according to claim 1, wherein the film thickness is displayed on a monitor disposed at a position visible to a worker who applies the wax.
A theory for deriving a theoretical formula indicating the relationship between the temperature difference between the back surface temperature of the coating region and the surface temperature before coating and the coating film thickness of the wax, based on the coating condition of the wax on the coated member. Further comprising an expression derivation step,
In the allowable lower limit setting step, based on the theoretical formula, a theoretical value of the allowable lower limit of the temperature difference corresponding to the allowable lower limit of the coating film thickness is calculated, and the theoretical value is calculated from the wax application region. The wax application range evaluation method according to claim 2, wherein an allowable lower limit value of the temperature difference is calculated by adding a temperature increase in the non-application area due to heat transfer to the non-application area.
Only the region where the actual temperature difference obtained by imaging with the infrared thermograph is equal to or larger than the allowable lower limit value of the temperature difference is displayed on a monitor disposed at a position visible to the wax application operator. The method for evaluating a coated area of the wax according to claim 2.
A coating inspection system for inspecting a coating state of a coating material on a member to be coated,
An infrared thermograph that images at least a coating region to which the coating material is coated among the coated members;
A display unit that is disposed at a position where a coating operator can visually recognize the temperature distribution of the coating region acquired by imaging the infrared thermograph;
The display unit is a coating inspection system capable of displaying a dynamic image that continuously displays a temporal change in the temperature distribution of the coating region and a still image at a predetermined time of the dynamic image.
The coating inspection system according to claim 8, further comprising: a display instruction unit for instructing display of the still image on the display unit by an operation; and a conveyance instruction unit for instructing conveyance of the coated member by a conveyance unit by the operation. .